1. Field of the Invention
The present invention generally relates to an ultra-low power/energy paradigm for memory, computing and information processing using multiferroic/magnetostrictive nanomagnets and, more particularly, to the use of planar multiferroic/magnetostrictive nanostructures as memory elements, two-state logic gates for traditional logic and four-state logic gates for performing higher order information processing. The invention includes novel multiferroic/magnetostrictive nanostructures design of memory elements, logic gates and other information processing elements with these structures, and processes for fabricating the same. These structures when used in memory or logic technology can potentially reduce energy consumption 1,000 to 10,000 times compared to the current state of the art, thereby enabling unique applications.
2. Background Description
The primary obstacle to continued downscaling of digital electronic devices in accordance with Moore's law is the excessive energy (or heat) dissipation that takes place in the device during switching. Unless this dissipation is reduced, downscaling of electronic devices and future progress will come to a stop. Current memory and logic circuits are very dissipative because they are transistor-based. Transistors use electron charge to encode information, which is inherently inefficient. Magnetic logic and memory systems, on the other hand, do not use charge to encode logic information; instead they use the magnetization of magnets to represent information. This can make them far less dissipative than transistors. Unfortunately, this advantage of magnets cannot be exploited unless the method employed to switch magnets is made energy-efficient. The magnetization of such single domain nanomagnets is usually switched with a spin-polarized current delivering a spin transfer torque. This technique is widely used in spin transfer torque random access memory (STTRAM). Unfortunately, this method of switching dissipates too much energy, and a more energy-saving approach is desirable. The invention described here fulfills this need since it is ˜100,000 times more energy-efficient than spin-transfer-torque switching magnets.